Skip to content

ol-interaction-snap

Handles snapping of vector features while modifying or drawing them.

Demo

Setup

Plugin usage

This component is part of the Interactions plugin. If not installed globally, you need to import and use the plugin in your main.ts or use the explicit component import (see section below).

Import and use the Interactions plugin
ts
import { createApp } from "vue";
import App from "./App.vue";

import {
  Map,
  Layers,
  Sources,
  Interactions,
} from "vue3-openlayers";

const app = createApp(App);
// ...
app.use(Interactions); 
// ...

Explicit import

If you don't want to install a plugin, you can import the component explicitly. It's available as a child of the named export Interactions.

NOTE

The following documentation refers to the plugin usage. Please make sure to adopt the component names, when you decided to use explicit component imports (e. g. <ol-map> becomes <Map.OlMap> etc.).

Usage

Plugin UsageExplicit Import
<ol-interaction-snap><Interactions.OlInteractionSnap>
vue
<template>
  <button class="btn-default" @click="drawEnabled = !drawEnabled">
    Draw: {{ drawEnabled }}
  </button>
  <ol-map
    ref="map"
    :load-tiles-while-animating="true"
    :load-tiles-while-interacting="true"
    style="height: 400px"
  >
    <ol-view
      ref="view"
      :center="center"
      :zoom="zoom"
      :projection="projection"
    />

    <ol-tile-layer>
      <ol-source-osm />
    </ol-tile-layer>

    <ol-vector-layer>
      <ol-source-vector :features="zones">
        <ol-interaction-draw
          v-if="drawEnabled"
          :stopClick="true"
          type="Polygon"
          @drawend="drawend"
        />
        <ol-interaction-snap v-if="modifyEnabled || drawEnabled" />
        <ol-style>
          <ol-style-stroke color="blue" :width="3" />
          <ol-style-fill color="rgba(0, 0, 255, 0.4)" />
        </ol-style>
      </ol-source-vector>
      <ol-interaction-modify v-if="modifyEnabled" :features="selectedFeatures">
        <ol-style>
          <ol-style-circle :radius="5">
            <ol-style-fill color="#00dd11" />
            <ol-style-stroke color="blue" :width="2" />
          </ol-style-circle>
        </ol-style>
      </ol-interaction-modify>
    </ol-vector-layer>
    <ol-interaction-select
      @select="featureSelected"
      :condition="selectCondition"
      :features="selectedFeatures"
    >
      <ol-style>
        <ol-style-stroke color="red" :width="2" />
        <ol-style-fill color="rgba(255, 0, 0, 0.4)" />
      </ol-style>
    </ol-interaction-select>
  </ol-map>
</template>

<script setup>
import { inject, ref } from "vue";
import { GeoJSON } from "ol/format";
import { Collection } from "ol";

const map = ref("");
const center = ref([-102.13121, 40.2436]);
const projection = ref("EPSG:4326");
const zoom = ref(5);
const modifyEnabled = ref(false);
const drawEnabled = ref(false);

const geojsonObject = {
  type: "FeatureCollection",
  crs: {
    type: "name",
    properties: {
      name: "EPSG:4326",
    },
  },
  features: [
    {
      type: "Feature",
      geometry: {
        type: "Polygon",
        coordinates: [
          [
            [-103.86923852630616, 43.45599322423934],
            [-103.90891107984544, 39.34240191087722],
            [-98.76630637117387, 39.558687199211114],
            [-98.89435771175386, 43.945405844902986],
            [-103.86923852630616, 43.45599322423934],
          ],
        ],
      },
    },
    {
      type: "Feature",
      geometry: {
        type: "Polygon",
        coordinates: [
          [
            [-103.85636392303468, 38.10970692739486],
            [-103.86770698495866, 33.218572724914544],
            [-98.20654544301988, 33.6532810221672],
            [-98.4408283538437, 38.31894739375114],
            [-103.85636392303468, 38.10970692739486],
          ],
        ],
      },
    },
  ],
};

const zones = ref([]);
const selectedFeatures = ref(new Collection());

const drawend = (event) => {
  zones.value.push(event.feature);
  selectedFeatures.value.push(event.feature);

  modifyEnabled.value = true;
  drawEnabled.value = false;
};

zones.value = new GeoJSON().readFeatures(geojsonObject);
const selectConditions = inject("ol-selectconditions");
const selectCondition = selectConditions.click;

function featureSelected(event) {
  modifyEnabled.value = false;
  if (event.selected.length > 0) {
    modifyEnabled.value = true;
  }
  selectedFeatures.value = event.target.getFeatures();
}
</script>

Properties

pixelTolerance

  • Type: Number
  • Default: 10

edge

  • Type: Boolean
  • Default: false

vertex

  • Type: Boolean
  • Default: false